Abstract: An ultrasonic surgical apparatus and method, the apparatus including a signal generator outputting a drive signal having a frequency, an oscillating structure, receiving the drive signal and oscillating at the frequency of the drive signal, and a bridge circuit, detecting the mechanical motion of the oscillating structure and outputting a signal representative of the mechanical motion. The ultrasonic surgical apparatus also includes a microcontroller receiving the signal output by the bridge circuit, the microcontroller determining an instantaneous frequency at which the oscillating structure is oscillating based on the received signal, and determining a frequency adjustment necessary to maintain the oscillating structure oscillating at its resonance frequency, the microcontroller further determining the quality (Q value) of the signal received from the bridge circuit and determining material type contacting the oscillating structure.

Abstract: An ultrasonic surgical apparatus and method, the apparatus including a signal generator outputting a drive signal having a frequency, an oscillating structure, receiving the drive signal and oscillating at the frequency of the drive signal, and a bridge circuit, detecting the mechanical motion of the oscillating structure and outputting a signal representative of the mechanical motion. The ultrasonic surgical apparatus also includes a microcontroller receiving the signal output by the bridge circuit, the microcontroller determining an instantaneous frequency at which the oscillating structure is oscillating based on the received signal, and determining a frequency adjustment necessary to maintain the oscillating structure oscillating at its resonance frequency, the microcontroller further determining the quality (Q value) of the signal received from the bridge circuit and determining material type contacting the oscillating structure.

Abstract: A hitch system includes a yoke pivotally supported by the ends of a rockshaft extending from the sides of the tractor housing. The yoke includes left and right side panels and a two-piece bottom. A drawbar is pivotally coupled to the yoke between the two bottom pieces. Left and right draft links have fore ends pivotally coupled to the yoke and are sway limited in the down position by sway links connecting each draft link with an inboard portion of the yoke. The draft links are sway limited in the raised position by sway surfaces on the sides of the yoke. Lift arms are splined to the rockshaft ends and are pivoted by a pair of lift cylinders coupled between the lift arms and the housing. A pair of lift links connect the lift arms to the draft links. A yoke positioning and draft sensing link includes a fore end connected to a bottom side of the housing and an aft end connected to the yoke.